All those gauges will return to their proper place unless you break them. The senders determine their position.
Note that the voltmeters on these (and probably other gauges as well) are calibrated by the placement of a little magnet in the case, which is held in by a dab of glue. With age the glue may become brittle. Be careful handling the gauges, and don't dislodge the magnets, or you'll have to recalibrate the gauges. If any gauge is not now accurate, though, this is the perfect time to make it accurate by moving the magnet and resticking it with something elastic like Shoe Goo. Of course you'll need trial and error for all but the voltmeter. For that you can do it on a bench with a variable power supply.